Automatic shift knob actuator

ABSTRACT

A stick shift handle assembly has a stick shift handle and an actuator for releasing the stick shift handle for movement between a plurality of gear positions. The actuator has a housing. A sleeve is disposed between the actuator and the housing. The sleeve has a first co-efficient of friction lower than a second co-efficient of friction of the housing.

FIELD OF THE INVENTION

This invention relates to an actuator for a stick shift handle assembly.

BACKGROUND OF THE INVENTION

A stick shift handle for an automatic transmission permits a driver tochange the gears of a vehicle transmission by moving the stick shifthandle between various positions. Typically, the stick shift handle islocked in a particular gear position until unlocked by the driver. Thedriver unlocks the stick shift handle by pressing a release buttoneither at the front of the stick shift handle or on its side, which, inturn, causes an actuator in the stick shift handle to release the stickshift handle from a shift lock mechanism.

Problems may arise with the actuator that unlocks the stick shifthandle. Specifically, the stick shift handle, which houses the actuator,is generally made from plastic and fiberglass. This material has a highco-efficient of friction and causes the actuator to experience a fairamount of friction when moved. While manufacturers have sought toovercome this problem by placing lubricant between the actuator and thestick shift handle, during frequent use, the lubricant tends to migratefrom the area of contact between the actuator and the stick shifthandle.

In addition, for a side actuating stick shift handle, manufacturers havesought to reduce the effort of unlocking the stick shift handle byemploying a cam as an actuator. To unlock the stick shift handle, thedriver presses a release button, which causes pivotal movement of thecam. The cam then moves an unlocking member along a linear path.However, the pivoting action of the cam tends to force the unlockingmember to move in a pivoting fashion as well. On occasion, this type ofmovement may cause a backlash through the release button. Manufacturershave sought to eliminate this problem by creating a notch in the cam toprevent the unlocking member from moving radially relatively to the cam.This fix is time consuming to implement.

A need therefore exists for a stick shift handle assembly that providessmooth and inexpensive actuation of a shift lock mechanism.

SUMMARY OF THE INVENTION

The present invention comprises a stick shift handle and an actuator forreleasing the stick shift handle for movement between various gearpositions. The actuator has a housing that is disposed within the stickshift handle. In contrast to existing stick shift handle assemblies,however, the inventive stick shift handle assembly employs a sleevebetween the actuator and its housing. The sleeve has a co-efficient offriction less than the co-efficient of friction of the housing or thestick shift handle. In this way, the actuator may slide on the sleevewith less frictional resistance than existing stick shift handleassemblies.

The actuator may have a flat surface that contacts a flat surface of thesleeve. Lubricant may be provided between the flat surfaces tofacilitate movement of the actuator within its housing. The flatsurfaces ensure that the lubricant will not migrate from the area ofcontact.

In addition, the sleeve may have a particular shape to match a shape ofthe housing. In this way, the sleeve will not move within the housing.The stick shift handle assembly may also employ a motion transmittingmember, such as a swizzle stick, to unlock a shift lock mechanism. Theactuator may also have a button, which has a sloped surface in contactwith another sloped surface of the actuator to allow motion to betransmitted from the button to the actuator in a smooth fashion.

For a side-actuating stick shift handle assembly, the inventive stickshift handle assembly employs a stick shift handle that moves betweenthe various gear positions along a first axis. Unlike a front actuationstick shift handle assembly, the side actuation stick shift handle usesan actuator that unlocks the stick shift handle by moving along a secondaxis transverse to the first axis. The actuator has a first member thatmoves along this second axis. In addition, a second member moves along athird axis to disengage the shift lock mechanism. The first member has afirst sloped surface while the second member has a second slopedsurface. The first member transmits motion to the second member throughthe sloped surfaces. In this way, motion may be transmitted along twodifferent paths with little resistance.

The first slope surface may be a rounded surface or an inclined surface.The first member may have a projection that fits into a groove of thehousing to prevent rotation of the first member within its housing. Inaddition, the housing may comprise a first portion extending along thesecond axis and a second portion extending along the third axis.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of this invention will becomeapparent to those skilled in the art from the following detaileddescription of the currently preferred embodiment. The drawings thataccompany the detailed description can be briefly described as follows.

FIG. 1 illustrates a stick shift handle assembly of a first embodimentof the invention, showing actuator and sleeve.

FIG. 2 illustrates an exploded view of the stick shift handle of FIG. 1,highlighting actuator and sleeve.

FIG. 3 illustrates the sleeve of FIGS. 1 and 2 with lubricant.

FIG. 4 illustrates the housing of FIGS. 1 and 2.

FIG. 5 illustrates a second embodiment of the invention, a sideactuation stick shift handle assembly.

FIG. 6 illustrates the actuator of FIG. 5.

FIG. 7 illustrates a cross-sectional view of the actuator of FIGS. 5 and6 in its housing.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a cross-sectional view of inventive stick shifthandle assembly 10. Like existing stick shift handle assemblies,inventive stick shift handle assembly 10 has stick shift handle 14,which allows a driver to shift a vehicle transmission through itsvarious gears. Stick shift handle 14 is prevented from moving from gearshift position to gear shift position by shift lock mechanism 50, hereshown schematically.

To release stick shift handle 14 for movement between the various gearshift positions, a driver presses button 60 in the direction of arrow C.Button 60 has first sloped surface 64, such as a rounded or inclinedsurface, which also moves in the direction of arrow C to contact secondsloped surface 68, here another rounded or inclined surface, of actuator18. Actuator 18 is housed in housing 22, which may be a separate part orbe part of stick shift handle 14. Actuator 18 then moves in thedirection of arrow A and transmits its motion to motion transmittingmember 54 to release shift lock mechanism 50. Following movement ofstick shift handle 14 to its proper gear shift position, motiontransmitting member 54 and actuator 18 move in the direction of arrow Band return button 60 to its original position along arrow D.

In contrast to existing stick shift handle assemblies, inventive stickshift handle assembly 10 employs sleeve 26 between actuator 18 andhousing 22. Sleeve 26 comprises a material having a lower co-efficientof friction C₁ than the co-efficient of friction of housing 22, C₂.Sleeve 26 thus offers a low amount of frictional resistance to actuator18 within housing 22.

As shown in FIG. 2, actuator 18 has first planar area 30 that fits ontop of second planar area 34 of sleeve 26. Accordingly, first planararea 30 slides on second planar area 34. To further reduce frictionbetween actuator 18 and sleeve 26, lubricant is placed on sleeve 26 atlocation 38 to allow actuator 18 to slide on sleeve 26 more smoothly.Because lubricant is placed between first planar area 30 and secondplanar area 34, movement of actuator 18 on sleeve 26 causes lubricant tospread evenly over the planar areas 30, 34 rather than in one particulararea. In this way, sleeve 26 prevents the migration of lubricant awayfrom the area of contact between actuator 18 and sleeve 26.

As shown in FIG. 3, sleeve 26 has first cross-section 42 of a particularshape to match, as shown in FIG. 4, the shape of second cross-section 46of housing 22. Moreover, second cross-section 46 has shoulders 48. Byhaving shoulders 48, sleeve 26 is prevented from rotating within housing22 and is, in fact, locked in place against rotational movement withinhousing 22.

FIGS. 5-7 illustrate side actuation shift assembly 100. Inventive stickshift handle assembly 100 has stick shift handle 104. Stick shift handle104 moves between gear shift positions along the X axis. As in theprevious embodiment, stick shift handle assembly 100 is prevented frommoving between gear positions by shift lock mechanism 150.

To release stick shift handle 104 for movement, a driver presses button102 in the direction of arrow E along the Y axis, as axis transverse tothe X axis, to contact actuator 108. Actuator 108 comprises first member124, which extends along the Y axis within first portion 116 of housing112, as well as second member 128, which extends along the Z axis, anaxis transverse to both the X and Y axes, within second portion 120 ofhousing 112. Movement of button 102 forces movement of first member 124in the direction of arrow E.

As shown in FIG. 6, first member 124 has first sloped surface 132, suchas a rounded or inclined surface, while second member 128 has secondsloped surface 136, such as a rounded or inclined surface. Accordingly,movement of first member 124 in the direction of arrow E causes firstsloped surface 132 to contact second sloped surface 136. Motion istransmitted from first member 124 along the direction of arrow E tosecond member 128 along the direction of arrow A, along the Z axis,through first sloped surface 132 and second sloped surface 136. Secondmember 128 moves motion transmitting member 154 to release shift lockmechanism 150 in the direction of arrow A. Once the gear shift positionhas been changed, motion transmitting member 154 returns along thedirection of arrow B to its original position. Motion transmittingmember 154 moves second member 128 in this same direction, whichultimately causes first member 124 and button 102 to return to theiroriginal positions along the direction of arrow F. This return andrelease function can be as known in the prior art. Thus, in contrast toother side actuation stick shift handle assemblies, inventive stickshift handle assembly 100 eliminates the cam as well as its pivotingaction. In this way, stick shift handle assembly 100 eliminates thebacklash associated with other side actuation stick shift handleassemblies.

In addition, first member 124 is provided with protrusion 140, as shownin FIGS. 6 and 7. As shown in FIG. 7, first portion 116 of housing 112is provided with groove 144 to receive protrusion 140. In this way,first member 124 is prevented from rotating within first portion 116 ofhousing 112.

The aforementioned description is exemplary rather that limiting. Manymodifications and variations of the present invention are possible inlight of the above teachings. The preferred embodiments of thisinvention have been disclosed. However, one of ordinary skill in the artwould recognize that certain modifications would come within the scopeof this invention. Hence, within the scope of the appended claims, theinvention may be practiced otherwise than as specifically described. Forthis reason the following claims should be studied to determine the truescope and content of this invention.

1-8. (canceled)
 9. A stick shift handle assembly comprising: a stickshift handle movable along a first axis; an actuator for releasing saidstick shift handle for movement, said actuator movable along a secondaxis transverse to said first axis; and a housing for said actuatorwherein said actuator comprises a first member extending along saidsecond axis and a second member extending along a third axis, said thirdaxis transverse to said first axis and said second axis wherein saidfirst member has a first sloped surface in contact with a second slopedsurface of said second member.
 10. The stick shift handle assembly ofclaim 9 wherein said first member is prevented from rotating about saidsecond axis.
 11. The stick shift handle assembly of claim 10 whereinsaid first member has a projection and said housing has a groove toreceive said projection, said groove extending along said second axis.12. The stick shift handle assembly of claim 9 wherein said housing hasa first portion extending along said second axis and a second portionextending along said third axis.
 13. The stick shift handle assembly ofclaim 9 including a shift lock mechanism for preventing movement betweenthe plurality of gear positions along said first axis. 14-17. (canceled)